Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02279169 2003-06-27
PARKING STAND FOR TRACTOR FRONT END LOADER
This invention concerns a loader having a loader boom to which a parking stand
is
attached, the stand including a support leg and strut respectively pivotally
mounted to the
boom for pivoting freely about first and second pivot axes between stored and
park positions
of the parking stand, with retaining structure being present to releasably
secure the stand in
the stored position and the strut then being operative when the stand is moved
to its park
position to anchor the support leg.
Background of the Invention
Loaders are mounted to agricultural or industrial vehicles such as, for
example,
agricultural tractors. They are frequently provided on the front side of the
vehicle, but may
also be attached to its rear side. When the loader is not needed, it can be
removed from the
vehicle and parked. For this purpose, known loaders are provided with parking
stands that
are pivotally mounted to the loader boom for movement between raised stored
positions and
lowered park positions. When parked, the loader is in a lowered condition so
as to be
supported in part by a bucket coupled to one end of the loader boom and
further by
respective support legs of the parking stands. When the loader is installed on
the tractor,
the support legs are swiveled upward into their stored positions in which they
are in contact
with the loader boom and are secured in the usual manner by retaining pins, or
the like, in
order to avoid interfering with the operation of the loader. In order to park
the loader, the
retaining pins must be removed so as to permit the support legs to swivel down
to their
parking positions. Beyond that, each parking stand includes a strut that is
also pivotally
attached to the loader boom. The strut is provided with a support component
which may be
engaged with the edge of an opening located in the support leg after the
support leg has
been pivoted to its park position. In order to assure a durable positive lock
between the
edge of the support leg opening and the support component of the strut, the
support
component is secured in the opening in the usual manner, for example, by means
of the
aforementioned retaining pin. After the loader is installed on the tractor,
the retaining
structure must be released, the strut and the support leg disconnected from
each other, and
both the strut and the supporting leg must be pivoted manually in the upward
direction. The
strut and unloading support must be separately guided manually so that the
strut comes to
lie between the support leg and the loader boom. While the known parking stand
arrangements function properly, the structure for permitting the movement of
the support leg
and strut between stored and park positions is not quite as simple as desired
which results in
the arrangement being more costly than is necessary.
CA 02279169 2003-06-27
Summary of the Invention
According to the present invention there is provided an improved parking stand
arrangement for a tractor front end loader.
An object of the invention is to provide a front end loader parking stand
arrangement
which is of a simple, compact construction which may be easily moved between
stored and
parking positions.
A more specific object of the invention is to provide a front end loader
parking stand
arrangement including a pair of support legs, which are each pivotally mounted
to a
respective arm of the loader boom, and including a pair of supporting strut
which
respectively hold the support legs in a stored position against the underside
of associated
loader arm when the strut is in its stored position and releasably secured to
the loader boom,
the strut having a support component in the form of a receptacle which is
brought into
engagement with a cross pin carried by the support leg when the support leg
and strut are
lowered to establish the parking stand park position.
These and other objects will become apparent from a reading of the ensuing
description together with the appended drawings.
Brief Description of the Drawings
FIG. 1 is a left side elevational view of a front end loader together with a
schematic
representation of a forward part of an agricultural tractor to which the
loader is attached.
FIG. 2 is an enlarged left side elevational view of a forward region of the
front end
loader showing its parking stand in a stored or transport position.
FIG. 3 is a view like FIG. 2 but showing the parking stand in a park position.
FIG. 4 is a sectional view taken along line 4 - 4 of FIG 3.
Description of the Preferred Embodiment
Preliminarily, it is to be noted that while some structure is described as
occurring in
pairs only one of the pair is depicted in the drawings with it to be
understood that the one of
the pair not illustrated is the same as, or the mirror image of, the one
shown.
A front end loader 10 is shown in FIG. 1 and is attached to the front side of
an
agricultural tractor which is only schematically indicated. At each side of
the tractor there is
provided a mast 12 having a pin 14 provided at its upper end and defining a
bearing to which
a rear end of a respective loader arm 18, defining opposite sides of a loader
boom, is
mounted for pivoting vertically. An implement, here shown as a bucket 20, is
connected to
the front ends of the loader arms 18 for pivoting vertically and so as to be
selectively
disconnected and interchanged with other implements. In order to raise the
bucket 20, the
loader arms 18 are pivoted about the pins 14 by a pair of hydraulic motors 26
respectively
coupled between each mast 12 and the associated loader arm 18. A further pair
of hydraulic
2
CA 02279169 2003-06-27
motors 27 are used to control the disposition of the bucket 20 about its
pivotal connections
with the forward ends of the arms 18.
Referring now to FIG. 2, there is shown the left-hand side of a parking stand
assembly, this side including a support leg 28 and strut 32, connected to the
left one of the
arms 18, with it being understood that another support leg 28 and strut 32 is
connected to
the right arm 18. Specifically, each support leg 28 includes a first end
region 34 attached
for pivoting vertically about a connection pin 36 received in a bushing
carried at an underside
of the respective arm 18. As can be seen in FIG. 4, each support leg 28
consists of a
parallel pair of side components 37 joined by a web or central component 38.
The central
component 38 is arranged between the side components 37 in such a way that at
least that
half of the support leg 28 which is remote from the connection pin 36 is
generally H-shaped
in cross section. The central component 38 is configured so as to include an
inclined
transition region 40 arranged between substantially parallel end regions 42.
In the transition
region 40, a rectangular opening 44 is provided whose edges 46 and 48 are
spaced
lengthwise along the support leg 28. Adjacent the second edge 48, a horizontal
cross pin 50
is rigidly fixed to the support leg 28.
The strut 32 is defined by a pair of opposite sides 52 interconnected by a web
53 so
as to form a channel which is U-shaped in cross section. The sides 52 at one
end of the
strut 32 project beyond the web 53 and are curved to form an arcuate stop
surface 54, and
are attached to the adjacent loader arm 18 for pivoting about a second pivot
axis defined by
a pin 55 located in a bracket fixed to the underside of the arm 18 above the
connection pin
36. The opposite sides 52 of the strut 32, at their ends which are remote from
the pin 55,
are provided with radiused notches or recesses which define an arcuate
receptacle 58. The
web 53 extends beyond the receptacle 58 and is back-turned to form a hook so
as to define
a latch element 60 that opens toward the receptacle 58, the function of the
latch element 60
being described below in greater detail.
The first and second pivot axes respectively defined by the connection pin 36
of the
support leg 28 and the coupling pin 55 of the strut 32 extend at least
approximately parallel
to each other and to a horizontal support plane for the loader 10. In the
stored position of
the parking stand shown in FIG. 2, the support leg 28 is swiveled upward so as
not to
interfere with the operation of the loader 10. The strut 32 then extends
through the opening
44 and is positioned within a first channel defined by the opposite side
components 37 of the
support leg 28 and the central component 38 and lies against the component 38
throughout
most of its length. On an opposite side of the component 38 from the first
channel, there is
formed a second channel in which is received an under side portion of the boom
arm 18 to
thereby secure the support leg 28 against sideways movement. As viewed in FIG.
2, the
3
CA 02279169 2003-06-27
upper end of the strut 32 is secured to the adjacent loader arm 18 by a
locking or retaining
structure 56, shown here as including a dowel pin welded to the boom arm 18
and received
in a hole provided in the web 53 adjacent the latch member 60, with a
releasable fastener
(not shown) being associated with the pin for holding the strut 32, and hence
the support leg
28, in place. The retaining structure 56 could however be in a form for remote
actuation
such as hooks or latches that may be operated by linkages or cable controls.
Alternatively,
the retaining structure could be of a sort actuated electrically,
hydraulically or pneumatically
preferably using power sources available on the tractor, but separate
arrangements may
also be provided. Further, a simple and cost effective retaining structure
could be made to
include an electromagnet. For example, through the use of an electromagnet, a
latch pin or
lock could be controlled, with the pin being spring biased to a latched
position so that when
the electromagnet is de-energized, even by a power failure, the parking stand
would remain
latched in its stored position.
In any event, when the retaining structure 56 is released, the support leg 28
tends to
automatically pivot downward due to the force of gravity. If the strut 32 is
manually
supported in this movement, then the support leg 28 moves to correspond to the
guided
movement of the strut 32. In order to bring the support leg 28 again into a
position in which
it is pivoted upward, the strut 32 is manually pivoted upward toward its
stored position.
Since the strut 32 extends through the opening 44, it is in contact with the
opening edge 46
during both upward and downward pivoting when the strut is manually moved. At
a point
where the strut 32 is approximately vertical, as shown in FIG. 3, the stop
surtace 54 will
prevent further downward movement of the strut 32 and the receptacle 58 will
move to a
position above the edge 48, and, hence, the pin 50, and, if the loader boom is
then lowered,
the pin 50 will become seated in the receptacle 58. The latch member 60 at the
end of the
strut 32 prevents the strut 32 from sliding out of the opening 44 as the hook-
shaped end of
the latch member 60 engages the pin 50 to positively stop downward movement of
the
support leg 28. Thereby a durable guidance is assured of the support leg 28 by
the strut 32.
This characteristic is advantageous, but it is not absolutely required for
successful
functioning of the invention.
In the park position shown in FIG. 3, the strut 32 is supported with its
receptacle 58
engaged with the pin 50. This park position is reached by the loader 10 after
the support leg
28 is swiveled downward, and subsequently raised slightly if necessary, by
lowering the
loader boom after the support leg 28 engages the ground, to thereby position
the pin 50
against the strut receptacle 58. Depending on where downward movement of the
strut 32 is
stopped by the engagement of the stop surface 54 with the boom arm 18, the
ends of the
strut sides 52 may come into contact with the inner section 42 of the web 38
prior to the pin
4
CA 02279169 2003-06-27
50 becoming engaged with the receptacle 58, the strut 32 then sliding
downwardly on the
section 42 until the receptacle 58 engages the pin 50. An additional securing
of the strut 32
in this position could be performed in the usual manner, for example, by means
of the
releasable fastener used at the retaining element 56, if no hook-shaped
element 60 is
provided on the strut 32.